JP2003347964A - Antenna duplexer and communication phone employing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna duplexer directly connected to a reception port of a balanced input. <P>SOLUTION: An antenna duplexer 14' is provided with a transmission filter 16 having an input terminal and an output terminal. The input terminal of the transmission filter 16 is connected to a transmission port of a mobile phone. The output terminal of the transmission filter 16 is connected to an antenna 12 of the mobile phone. The duplexer has a reception filter 18' of a dual mode surface acoustic wave type. The reception filter 18' has an input terminal and a balanced output terminal. An input terminal of the reception filter 18' is connected to the antenna 12. An output terminal of the reception filter 18' is directly connected to a balanced input reception port of the mobile phone. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an antenna duplexer used for a mobile communication telephone (portable telephone) and a communication telephone using the same.

[0002]

2. Description of the Related Art As shown in FIG. 1, a portable telephone usually includes a communication unit 10 having a transmission port TX and a reception port RX. The transmission port and the reception port share a common antenna 12.

[0003] Today's communication systems require full-duplex communication capabilities, ie, electronic circuitry that allows simultaneous transmission and reception by the user. Although duplex transmission can be realized in various ways, the method adopted is usually determined by the multiplex transmission method. Multiplex transmission is used to enable a plurality of users to simultaneously access a communication network. For example, GSM (Global System for Global
There are a time division multiple access (TDMA) system, a frequency division multiple access (FDMA) system, and a code division multiple access (CDMA) system widely adopted in North America in recent years. In TDMA systems, duplex transmission is typically achieved by electronic switching between a transmit port and a receive port, and at a given time only one of the transmit and receive ports is electrically connected to the antenna. It has become. In FDMA and CDMA systems,
Both the transmission port and the reception port are connected to the antenna at the same time.

As shown in FIG. 1, a conventional antenna duplexer (branch circuit) 14 has three single-ended ports. Of these ports, a first port is connected to a receiver of the telephone, a second port is connected to a transmitter of the telephone, and a third port is a common antenna 1.
2 are connected. The purpose of the antenna duplexer is
By realizing the separation of the transmission signal and the reception signal, the high frequency (RF) output from the transmission port is efficiently supplied to the antenna, and the high frequency output from the transmission port leaks to the reception port, and a desired reception signal and The goal is to avoid interference. Further, since the attenuation of the reception signal from the antenna leads to a decrease in sensitivity at the reception port of the mobile phone, the duplexer 14 needs to prevent the reception signal from the antenna from attenuating.

[0005] For example, a conventional antenna duplexer as described in Patent Document 1 has two band-pass filters 16 and 18 arranged on a substrate as shown in FIG.
It has. One of these filters (hereinafter referred to as a transmission filter) 16 is designed to have a passband that matches the transmission band of the mobile communication system used. The other filter (hereinafter,
Described as a reception filter. ) 18 are designed to have a passband that matches the reception band of the mobile communication system being used. Generally, the transmission filter and the reception filter are dielectric filters. The substrate further includes an input terminal, an output terminal, and a metal track so that the transmission filter and the reception filter can be connected to the transmission port and the reception port of the mobile phone and the antenna. Further, the duplexer 14 includes a matching circuit 20 designed to maximize the isolation between the transmission filter 16 and the reception filter 18. The matching circuit 20 includes a microstrip line or a discrete element such as an inductor or a capacitor.

For example, as disclosed in Patent Document 2, a duplexer having two ladder-type surface acoustic wave (hereinafter, also referred to as SAW) filters instead of the above-described dielectric filter is also known. . FIG. 2 shows main features of a SAW resonator which is a component of such a filter. This resonator includes an interdigital converter (hereinafter, referred to as IDT) having an input terminal In and an output terminal Out. The IDT further includes a set of busbars 50 and 53 and electrode fingers. One bus 50
Is connected to the input terminal In of the resonator, and the other bus 5
3 is connected to the output terminal Out of the resonator. The electrode fingers are alternately connected to the input bus 50 and the output bus 53 of the IDT. Reflectors 57 are provided at both ends of the IDT, and these reflectors 57 further include electrode fingers. The electrode fingers of the reflector 57 may be electrically separated from each other, or may be electrically connected to each other via metal lines disposed above and below the electrode fingers of the reflector. A SAW resonator having an IDT, a bus bar, a reflector, an input end and an output end is disposed on a piezoelectric substrate formed by, for example, lithium tantalate, lithium niobate, quartz or langasite.

FIGS. 3 (a) and 3 (b) show π-type and T-type ladder-type SAW filters, respectively. Here, each filter has an input terminal In and an output terminal Out.
And the series SAW resonators 3 alternately arranged between
1 and a parallel SAW resonator 32. The conventional ladder-type filter is usually designed so that the resonance frequencies (f1) of all the series resonators 31 are the same and the resonance frequencies (f2) of all the parallel resonators 32 are also the same. I have. Normally, the resonance frequency f1 is changed to the resonance frequency f2.
By making the resonance frequency sufficiently higher than the above, the resonance frequency of the series resonator 31 is substantially equal to the anti-resonance frequency of the parallel resonator 32.

FIG. 4 shows an antenna duplexer using two ladder-type SAW filters. In this antenna duplexer, a ladder-type SAW filter shown in FIG.
The ladder type S shown in FIG.
An AW filter is used. In FIG. 4,
TX represents a transmission input terminal, and RX represents a reception output terminal.

The advantage of using a SAW filter instead of a dielectric filter in an antenna duplexer is as follows.
That is, the entire size of the duplexer can be reduced. This is especially important in the field of mobile phones, where the feasibility of commercialization greatly depends on the overall size of the phone. However, particularly for realizing high output handling performance, the metal used for the IDT of the SAW filter, which is a main component, needs to be selected with particular consideration. This is because the main drawback of using a SAW filter in an antenna duplexer is that the power handling capability is reduced. Patent Literature 3 and Patent Literature 4 disclose a metal electrode having high power resistance performance suitable for a SAW filter. The metal electrode includes an electrode made of aluminum, an electrode made of an aluminum alloy, and an electrode made of another metal.

[0010]

[Patent Document 1] European Patent Application Publication No. 0667685

[Patent Document 2] European Patent No. 0928064

[Patent Document 3] US Pat. No. 6,316,860

[Patent Document 4] US Pat. No. 5,929,723

[0011]

All of the prior art systems described above operate with a receiving port for receiving an unbalanced signal, ie, a single signal line as shown in FIGS. 3 and 4, for example. It is supposed to. However, in the telecommunications industry, it is often desired to employ an electronic circuit having a balanced circuit configuration. That is, while the electric signal is split between the two signal lines and the amplitude of both electric signals is equal,
The configuration is such that both electric signals have a phase difference of 180 degrees. The balanced circuit configuration is less sensitive to noise than the unbalanced circuit configuration, resulting in a higher sensitivity of the receiver.

However, the ladder type SAW filter is
Only an unbalanced signal can be output. Therefore, when an antenna duplexer using this ladder-type SAW filter is used in a mobile phone, an unbalanced-balanced converter (balun) is connected between the reception output terminal of the antenna duplexer and the reception port of the mobile phone. There is a need. Using an unbalanced-balanced converter has two adverse effects. First, the size increases due to the addition of components, and second, unavoidable loss caused by introducing additional components.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an antenna duplexer for connecting a transmission port and a reception port of a portable telephone to an antenna, which can be directly connected to a balanced input reception port. It is an object of the present invention to provide an antenna duplexer and a communication telephone using the same.

[0014]

An antenna duplexer according to the present invention includes a transmission filter and a dual mode surface acoustic wave type reception filter. The transmission filter has an input terminal configured to be connected to a transmission port of the mobile phone, and an output terminal configured to be connected to an antenna for the mobile phone. The receiving filter has an input configured to be connected to the antenna and a balanced output configured to be directly connected to the balanced input receiving port of the mobile phone.

The duplexer of the present invention allows a single-ended output terminal of a transmitting section of a portable telephone to be connected to an antenna of the telephone, and at the same time connects the antenna to a balanced input terminal of a receiving section of the telephone. Enable.
The duplexer may have an output of a receive filter that is optimally matched to the input impedance of the receiver of the telephone. Further, the duplexer can be changed to a conventional unbalanced reception output type simply by replacing the reception SAW filter included in the duplexer. Since the change to the unbalanced output receive filter does not require other changes in the duplexer configuration, the duplexer of the present invention is easily modified for compatibility with mobile phones of any type of receiver configuration. be able to. Therefore, only a single duplexer package having the same pin arrangement, transmission filter, matching circuit and substrate can be used for a receiving circuit having a single-ended input terminal or a receiving circuit having a double balanced input terminal. An antenna SAW duplexer that can be directly connected can be realized.

The duplexer according to the present invention can realize good isolation between the output terminal of the transmitting unit of the telephone and the input terminal of the receiving unit of the telephone, and furthermore, provides a good connection between the output terminal of the transmitting unit and the antenna. , And the loss between the antenna and the receiver is small. The present invention eliminates the need for the unbalanced-to-balanced converter normally required to convert the unbalanced received output from the antenna duplexer to a balanced output required by a receiver having a balanced input.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, FIG. 5 shows an antenna duplexer 14 'according to a preferred embodiment of the present invention.
FIG. The duplexer 14 'is, for example, a GS
It is configured to operate in one of an M communication network and a broadband CDMA communication network. Duplexer 14 '
Includes a package substrate formed of a plastic material such as, but not limited to, alumina (ceramic) or bismaleimide triazine (BT) resin. If alumina is used, the substrate can be formed by a multi-layer ceramic low temperature firing (LTCC) process. Ladder type SA on the substrate
A W transmission filter 16 and a dual mode (hereinafter, also referred to as DMS) type SAW reception filter 18 'are mounted. The transmission filter 16 has an input terminal TX IN configured to be connected to a transmission port of a transmission unit of the mobile phone.
And an output end configured to be connected to the antenna 12 of the mobile phone. The reception filter 18 '
An input end configured to be connected to the antenna 12,
It has balanced output terminals RXOUT1 and RXOUT2 configured to be connected to the reception port of the reception unit of the mobile phone. The duplexer 14 'further includes a matching circuit 20 formed to maximize the isolation between the transmission filter 16 and the reception filter 18'. The matching circuit 20 can be configured by a matching strip line or a combination of discrete elements such as inductors and capacitors, as in the related art. When a multilayer ceramic substrate is used, the matching circuit 20 may be integrated with the substrate.

The package substrate further includes a transmission input terminal, a reception output terminal, and an antenna terminal. They are,
The duplexer 14 ′ can be electrically connected to the transmitting unit of the mobile phone, the receiving unit of the mobile phone, and the antenna 12. Transmit filter 16, Receive filter 1
Metal tracks are arranged on the substrate so that the 8 'and the matching circuit 20 can be electrically connected to the terminals of the package substrate. The matching circuit 20 is disposed between the transmission filter 16 and the reception filter 18 ', and is electrically connected thereto. In particular, in the example shown in FIG. 5, the matching circuit 20 is connected between the input terminal of the reception filter 18 ′ and the antenna 12. Transmit filter 16 and receive filter 18 'include pads for electrical connection to metal tracks on the substrate. Transmission filter 1
6 and the receiving filter 18 'are electrically connected to the metal tracks using metal bonding wires extending between the pads of the filter and the metal tracks, or by using flip-chip connections. When flip-chip connections are used, solder balls, gold bumps or other suitable connection means may be used as the connection means to achieve electrical connection between the pads of the SAW filter and the metal tracks of the package substrate. it can.

As the transmission filter 16 in the present invention, a SAW type or any other type of filter that can be stored in a package of an antenna duplexer can be used. The transmission filter 16 has a pass band that matches the transmission band of the mobile communication system in which the duplexer is used. The transmission filter 16 further has a stop band in the reception band of the mobile communication system. The transmission filter 16 may be a band-pass filter, a low-pass filter, or a notch type. When the transmission filter 16 is a SAW type, any of a so-called ladder type SAW filter, a notch type SAW filter, and a dual mode SAW filter shown in FIG. 5 may be used. Similarly, the reception filter 18 'may be a band-pass filter, a low-pass filter, or a notch type.

The receiving filter 18 'has a pass band that matches the receiving band of the mobile communication system in which the duplexer is used. The reception filter 18 'further has a stop band in the transmission band of the mobile communication system. In any case, the present invention provides an antenna duplexer that can directly connect the reception output terminal of the duplexer to the double balanced input terminal of the reception input port of the mobile phone.

Next, a detailed configuration of the reception filter 18 'will be described. FIG. 6A shows the main features of a one-stage DMS type SAW filter having an unbalanced output terminal. FIG. 6B shows the main features of a one-stage DMS type SAW filter having a balanced output terminal. In each case, the DMS SAW filter is
DT21 is provided. Center IDT2 with standard configuration
1 has a plurality of electrode fingers. The electrode fingers are arranged perpendicular to the direction of propagation of the SAW energy,
The upper bus 50 and the lower bus 53 are connected alternately. In this specification, the terms “upper” and “lower” are used only when referring to the drawings, and do not mean the arrangement direction of the devices actually used. Center I
On both sides of DT21, outer IDT22L,
22R are arranged. Outer IDT22L, 22R
Has basically the same structure as the center IDT 21 and has an upper bus 51 and lower buses 52 'and 52 ". Usually, the number of electrode fingers of each of the outer IDTs 22L and 22R is the same as that of the center IDT 21. , But the sum of the electrode fingers of the outer IDTs 22L and 22R is greater than the number of electrode fingers of the center IDT 21. The three IDTs are the left outer IDT 22L and the center IDT.
21 and a right outer IDT 22R. A set of reflectors 23 is provided on both sides of the block. Center IDT21 and outer IDT22
L, 22R and each IDT 21, 22.
By adjusting the number of electrode fingers of 2L and 22R, 2
It is possible to cause propagation of two longitudinal SAW modes between two reflectors 23. Also, the center IDT 21
The bandwidth of the SAW filter can be optimized by adjusting the gap 54 between the outer IDTs 22L and 22R and the number of electrode fingers of each IDT 21, 22L and 22R.

Each IDT bus 50-53 is directly or indirectly connected to one of the input pads or output pads of the SAW chip via conductive signal lines.
6A and 6B, the upper bus 50 of the center IDT 21 is connected to the input terminal IN, and the upper bus 51 of the outer IDTs 22L and 22R is grounded. Similarly, the lower bus 53 of the center IDT 21 is grounded. However, in the case of the unbalanced output terminal shown in FIG. 6A, the lower buses 52 'and 52 "of the outer IDTs 22L and 22R are connected to each other and further to a single output pin OUT. 6B, the lower bus 5 of the outer IDTs 22L and 22R
2 ', 52 "are output pins OUT1, OUT, respectively.
2 are connected. As described above, the electrode fingers of the center IDT 21 are alternately connected to the input terminal or grounded, and the electrode fingers of the outer IDTs 22L and 22R are alternately connected to one of the output terminals or grounded. Outer IDT22
Depending on the polarity of the electrode finger closest to the end of the center IDT 21 among the L and 22R electrode fingers, the output of the filter has the same phase or a phase difference of 180 degrees. However, this type of filter can be configured to produce a single unbalanced output or a double balanced output.

The receiving DMS filter 18 'of the duplexer 14' may have a one-stage filter as shown in FIGS. 6A and 6B, or may have a multi-stage filter. As an example, FIG. 7 shows a two-stage D
3 shows an MS-type SAW filter. This filter includes a set of single-stage filters 60 and 62. here,
The output of the first stage filter 60 is unbalanced, and the output of the second stage filter 62 is balanced. The output signal of the first-stage filter 60 is connected to a single input terminal of the second-stage filter 62, and a balanced output is generated from the second-stage filter 62, so that the overall configuration of the filter is , A set of DMS filter stages cascaded in series.

FIGS. 8A and 8B show another configuration of the DMS type SAW filter. In these configurations, the upper bus 51 of each of the outer IDTs 22L, 22R is connected to the input end IN of the receiving filter, and
The lower buses 52 'and 52 "of the 2R are grounded. Therefore, the electrode fingers of the outer IDTs 22L and 22R are alternately connected to the input terminal IN or grounded. Instead of extracting the balanced or unbalanced output from the outer IDTs 22L and 22R, the balanced or unbalanced output is extracted from the center IDT 21. In the unbalanced configuration shown in Fig. 8A, the bus 50 is grounded and the bus 50 is grounded. 53 is connected to the output terminal OUT In the case of the balanced configuration shown in FIG.
Is a conventional folded type IDT. Return type ID
T has three buses, one bus 50 of which runs the entire length of the IDT. The other two buses 53
Are about half the length of the opposite side of the IDT, respectively. In this configuration, a half-length bus 53 is connected to each output pad OUT1, OUT2 of the filter, respectively.
On the other hand, the bus 50 over the entire length is not connected anywhere and has a floating potential.

A DMS of the type shown in FIG.
Filter of the duplexer 14 '
8 ', it is possible to directly connect the receiving circuit of the mobile phone to the balanced input terminal. However, because of the direct connection to the receiving circuit with unbalanced inputs, it is easy to change the chip of the receiving filter to the type shown in FIG. 6A or 8A so as to obtain a single-ended output from the antenna duplexer. is there.

In this connection, with an unbalanced output,
Table 1 shows the filter parameters for a DMS SAW filter of the type shown in FIG. 8A. This SAW filter is suitable, for example, for a wideband CDMA telephone having a single line receiving port. Table 2 shows the filter parameters for a DMS type SAW filter of the type shown in FIG. 8B with a balanced output. This SAW filter is, for example, a wideband CDMA having a double balanced receiving port.
It is suitable for telephones of the type. In both cases,
Although the substrate is formed of lithium tantalate and the electrodes (electrode fingers) are formed of aluminum, the present invention is not limited to these materials. The substrate is
For example, lithium tantalate, lithium niobate,
Formed by quartz and one of the langasite. The electrode includes, for example, one of aluminum, an aluminum alloy, and another metal, and may be a single layer or a multilayer. At the request of the mobile phone manufacturer,
The improved duplexer of the present invention is interchangeable with a duplexer having an unbalanced output.

[0027]

[Table 1]

[0028]

[Table 2]

The transmission filter and the reception filter of the present invention are:
Includes pads for electrical connection to metal tracks on the package substrate. These pads are divided into input pads, output pads, and ground pads. The transmit and receive filters have no electrical function, but
The duplexer of the present invention may include pads to achieve structural integrity. Such pads are included in cases where the electrical connection between the transmit and receive filters and the metal tracks of the package substrate is made by flip-chip connections. This is because when the flip-chip connection is used, the pads of the filter need to be arranged at predetermined positions for accurate alignment between the pads of the filter and the metal tracks of the package substrate.

Further, it is desirable that the duplexer of the present invention can be changed from the balanced reception output type to the unbalanced reception output type only by replacing the balanced output reception SAW filter with the unbalanced output SAW filter. However,
To facilitate this exchange, the input pad, output pad and ground pad of both the balanced and unbalanced output receiving SAW filters must be co-located.

FIG. 10A shows an example of the arrangement of the DMS type SAW filter structure of FIG. 8A on a piezoelectric substrate. FIG.
8B shows an example of the arrangement of the DMS type SAW filter structure shown in FIG. 8B. It can be seen that the pad arrangement shown in FIGS. 10A and 10B satisfies the conditions for realizing the above-described replaceable function. 10A and FIG.
In the pad arrangement shown in B, the arrangement of the input pad IN, the output pad OUT, and the ground pad GND is the same.

In the case of FIG. 10B, the center ground pad GND on the SAW chip is the DMS type SAW reception filter 1.
8 'is not electrically connected to any part. In this case, the purpose of the bump attached to the central ground pad is only to preserve the structural integrity of the duplexer package. 10A and 10B,
Pad N / C is also a DMS type SAW receiving filter 18 '.
However, it is not electrically connected to any part.

Next, FIGS. 9A to 9C show examples of the package structure of the antenna duplexer of the present invention. These configurations each have two receive output pins “RX O /
P1 ”and“ RX O / P2. ”When a balanced output type DMS filter is used, the reception output pin“ R
XO / P1 "and" RXO / P2 "supply balanced inputs to the communication section of the telephone, while unbalanced output type D
When the MS filter is used, the reception output pin “RX O /
One of P1 "and" RX O / P2 "becomes redundant, while the other supplies a single signal line output. In the case where an unbalanced output type DMS filter is used, the unbalanced signal is supplied to two reception output pins “RX O / P1” and “RX O”.
/ P2 ", and these two pins may both be connected to an external printed circuit board on which the duplexer is mounted. As still another method, an unbalanced output type DMS filter is used. If so, a package with one less pin may be used.

The package structure shown in FIGS. 9A to 9C further includes a transmission input pin “TXI / P”, an antenna pin “Antenna”, a ground pin “Gnd”, and an unused pin “Unused”.

From the above description, it can be seen that the DMS filter used as the receiving filter 18 'of the antenna duplexer can be formed using various configurations as summarized below. (1) A configuration in which the transmission filter is a ladder-type SAW filter and the reception filter is the DMS-type SAW filter of FIG. 6B. In this case, the DMS SAW filter of FIG. 6B can be replaced with the DMS SAW filter of FIG. 6A. (2) A configuration in which the transmission filter is a ladder type SAW filter and the reception filter is the DMS type SAW filter of FIG. 8B. In this case, the DMS type SAW filter of FIG. 8B can be replaced with the DMS type SAW filter of FIG. 8A. (3) The transmission filter is another type of SAW filter,
A configuration in which the reception filter is the DMS SAW filter of FIG. 6B or 8B. In this case, D in FIG. 6B or FIG.
The MS type SAW filter is the DMS of FIG. 6A or FIG. 8A.
It can be replaced with a type SAW filter. (4) The transmission filter is another type of filter other than the SAW filter, and the reception filter is D in FIG. 6B or 8B.
Configuration that is an MS type SAW filter. In this case, the DMS-type SAW filter of FIG. 6B or 8B can be replaced with the DMS-type SAW filter of FIG. 6A or 8A.

[0036]

As described above, according to the present invention,
An antenna duplexer that can be directly connected to a balanced input receiving port can be realized.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a conventional antenna duplexer.

FIG. 2 is a perspective view showing a conventional surface acoustic wave (SAW) resonator.

FIG. 3 is a circuit diagram showing a conventional ladder type SAW filter.

FIG. 4 is a circuit diagram showing a conventional SAW antenna duplexer using a ladder-type filter.

FIG. 5 is a circuit diagram illustrating an antenna duplexer of the present invention including a balanced output receiving unit.

FIG. 6A is a conventional one-stage DM having an unbalanced output terminal.
FIG. 3 is a circuit diagram illustrating a first configuration of an S-type SAW filter.

FIG. 6B is a conventional one-stage DMS having a balanced output terminal.
FIG. 2 is a circuit diagram showing a first configuration of a type SAW filter.

FIG. 7 is a circuit diagram showing a conventional two-stage DMS type SAW filter having a balanced output terminal.

FIG. 8A is a conventional one-stage DM having an unbalanced output terminal.
FIG. 9 is a circuit diagram illustrating a second configuration of the S-type SAW filter.

FIG. 8B is a conventional one-stage DMS having a balanced output terminal.
FIG. 4 is a circuit diagram showing a second configuration of the type SAW filter.

FIG. 9A is a plan view showing an example of a pin array of the antenna duplexer according to the embodiment of the present invention.

FIG. 9B is a plan view showing another example of the pin arrangement of the antenna duplexer according to the embodiment of the present invention.

FIG. 9C is a plan view showing still another example of the pin arrangement of the antenna duplexer according to the embodiment of the present invention.

FIG. 10A is a plan view showing an arrangement of the DMS type SAW filter shown in FIG. 8A on a piezoelectric substrate.

FIG. 10B is a plan view showing the arrangement of the DMS type SAW filter shown in FIG. 8B on a piezoelectric substrate.

[Explanation of symbols]

12 ... antenna, 14 '... antenna duplexer, 16
... a transmission filter, 18 '... a reception filter, 20 ... a matching circuit.

Claims (17)

[Claims] 1. A transmission filter having an input terminal configured to be connected to a transmission port of a mobile phone, and an output terminal configured to be connected to an antenna for the mobile phone, and connected to the antenna. An input end configured to be
An antenna duplexer comprising: a dual mode surface acoustic wave type reception filter having a balanced output end configured to be directly connected to a balanced input reception port of the mobile phone. 2. The antenna duplexer according to claim 1, further comprising a package having a substrate on which the transmission filter and the reception filter are mounted. 3. The antenna duplexer according to claim 2, wherein said substrate is formed of alumina. 4. The antenna duplexer according to claim 1, further comprising a matching circuit electrically connected between said transmission filter and said reception filter. 5. The antenna duplexer according to claim 4, wherein the matching circuit is connected between the reception filter input terminal and the antenna. 6. The antenna duplexer according to claim 4, wherein said matching circuit includes a microstrip line. 7. The antenna duplexer according to claim 4, wherein said matching circuit includes a combination of an inductor and a capacitor. 8. The transmission filter according to claim 1, further comprising one of a ladder type surface acoustic wave filter, a dual mode type surface acoustic wave filter, and a filter other than the surface acoustic wave filter. 2. The antenna duplexer according to 1. 9. The antenna duplexer according to claim 1, wherein the receiving filter includes a substrate formed of one of lithium tantalate, lithium niobate, quartz, and langasite. . 10. The antenna duplexer according to claim 1, wherein the reception filter includes a single-layer or multi-layer electrode including one of aluminum, an aluminum alloy, and another metal. 11. The antenna duplexer according to claim 1, wherein each of the transmission filter and the reception filter includes one of a band-pass filter, a low-pass filter, and a notch-type filter. 12. The antenna duplexer according to claim 11, wherein each of the transmission filter and the reception filter has a stop band in a pass band of the other filter. 13. The antenna duplexer according to claim 1, wherein each of the transmission filter and the reception filter is configured to transmit and receive a signal between the antenna and the antenna at the same time. 14. The antenna duplexer according to claim 1, wherein the antenna duplexer is configured to operate in one of a GSM communication network and a broadband CDMA communication network. 15. The antenna duplexer according to claim 1, wherein the reception filter includes a double mode surface acoustic wave filter having a plurality of stages. 16. The apparatus according to claim 2, wherein the substrate is configured such that the receiving filter having a balanced output terminal and the receiving filter having an unbalanced output terminal can be interchangeably mounted. Antenna duplexer. 17. A communication telephone comprising: a communication unit including a transmission port and a reception port; and the antenna duplexer according to claim 1, wherein the impedance of the balanced output terminal is equal to that of the reception port of the telephone. A communication telephone characterized by matching input impedance.